Enclosures for sound reproduction



p 1957 R. L. SEWELL ENCLOSURES FOR SOUND REPRODUCTION Filed Jan. 11, 1954 6 L 6 L R N m N a .2 W 1 m Emu W M a a v 2 V.- Q B United States PatentOfiFice 2,806,547 ENCLOSURES FOR SOUND REPRODUCTION Robert L. Sewell, Santa Ana, Calif. Application January 11, 1954, Serial No. 403,242 6 Claims. (Cl. 181-31) The present invention relates to enclosures for loud speakers used in reproduction of sound.

The arrangements described herein are featured by their simplicity, rigidity and enhanced quality of the reproduced sound, these features being attributed largely to the fact that the enclosure has internally disposed baffie members so arranged that any particular space in the enclosure is defined by walls extending in non-parallel relationship.

A general object of the present invention is to provide an improved enclosure whereby the above indicated results may be achieved.

A specific object of the present invention is to provide a speaker enclosure having chambers therein defined by walls extending in non-parallel relationship.

Another specific object of the present invention is to provide an improved enclosure so constructed as to prevent the formation of standing waves to thereby assure substantially no intermodulation distortion or harmonic distortion.

Another specific object of the present invention is to provide an enclosure having substantially only one resonant frequency and which may be enharmonic of the resonant frequency of the loaded cone of the speaker used in conjunction with such enclosure.

Another object of the present invention is to provide improved enclosures which are suitably braced mechanically by the bafile members so as to greatly minimize what is termed in the art as cabinet breathing, thereby obtaining relatively high efiiciency in the conversion of sound transfer, particularly at low frequencies.

Another specific object of the present invention is to provide improved enclosure construction which requires no internal padding, thereby again assuring high, efficient energy transfer.

Another specific object of the present invention is to provide improved enclosure construction involving socalled front radiation only and which, in providing high fidelity sound reproduction, requires no multiple paths which may otherwise cause cancellation and reinforcements as, for example, in arrangements using a backloaded horn and a so-called base reflex principle.

Another specific object of the present invention is to provide an enclosure reproductive of high fidelity sound, having relatively small physical size and which is relatively inexpensive.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

Figure 1 is a view showing in perspective a cabinet construction or enclosure embodying features of the present invention.

Figure 2 is a perspective view, as in Figure 1, with some of the external walls of the cabinet shown in Figure 1 re- 2,806,547 Patented Sept. 17, 1957 moved to illustrate the internal arrangement of the bafile members.

Figure 3 is a perspective view of the three baifie members used in the cabinet construction of Figures 1 and 2.

Figures 4 and 5 are sectional views taken substantially on the lines 4-4 and 5-5 of Figure 1.

Figure 6 is a perspective view similar to the cabinet illustrated in Figure 2, but a modified arrangement which, instead of using three bafile members, uses only two baffle members.

Figure 7 is a sectional view taken line 7-7 of Figure 6.

Figure 8 is a view partly in elevation and partly in section, looking down from the top of another modified cabinet construction which, in this instance, is a corner cabinet.

Figure 9 is a view taken generally on the line 9-9 of Figure 8.

The enclosure or cabinet in the first modification illustrated in Figures l5 comprises a six-sided rectangular box having three baffie members of unique construction, which are uniquely disposed internally of the rectangular box to define a plurality of chambers, such chambers being defined by non-parallel walls. The box 10 includes the six walls 12, 13, 14, 15, 16 and 17 and the bafile members disposed therein have the reference numerals 18, 19 and 20.

While the center baffie member 19, which is generally rectangular as shown in Figure 3, is preferred for mechanical rigidity to prevent cabinet breathing, the same is preferably used but is not considered essential for achieving more particular concepts of the present invention, as will be more clear from a comparison of the structures illustrated on the one hand in Figure 1 and on the other hand in Figure 6.

The use of the triangular bafiie member 18 is considered important and in the first two modifications illustrated herein, i. e., in Figures 1 and 6, the apex 18A of the triangular baffle member 13 and the apex 20A of the triangular baffie member 20 are disposed in corners of the box 10 which lie at the ends of a diagonal of a particular internal face of the rectangular box or enclosure, while the base 183 and the base 20B of the triangular bafile members 18 and 20, respectively, contact each other on a line corresponding to a diagonal of a face which is opposite to and extends parallel to the aforementioned internal face. Thus, as shown in Figure 1, the apex 18A and the apex 29A are disposed in threesided corners 10A and 10B of the box 10, which corners are at the ends of a diagonal of the internal face of wall 14; and the bases 18B and 20B contact each other on a line which corresponds to the diagonal of the internal face of the wall 12, such walls 12 and 14 being opposite walls extending parallel to each other.

The center baffie member 19, when used, extends between the triangular bafile members 18 and 20 and between diagonally opposite two-sided corners 10C and 10D of the box 10. Using this construction, it is seen that the internal space of the rectangular box is divided into a plurality of chambers, each of which is defined by nonparallel walls. The particular face on which a conventional loud speaker of the cone type (as is commonly used in radios and television sets) is mounted, involves to a certain extent a matter of choice and, as shown in Figsubstantially on the ure 1, such speaker is intended to be mounted in the central portion of the wall 12, i. e., that wall which is contacted internally by the three bafiie members 18, 19 and 20 on substantially the same diagonal line. In order to provide clearance for such speakers, the bafile members 18, 19 and 20 are routed out, as shown in Figure 2, to accommodate the rearwardly extending body of the speaker which generally has a cylindrical housing or base joined to a conical shaped housing. The degree to which the battle members are routed" out is sufficient only to prevent engagement of the body of the speaker with the bafiiemembers. Otherwise, the. chambers. definedby the bafile members may be in communication with each other at the. place; where the. three. bafiie. members. are routed out,.as.mentioned ab.ove..

The arrangements shown in.Fi'g ure 6'illustrate the conditions wherein the. central bafii'e member 19 is omitted and, in. general, corresponding parts. in Figures 1 and 6' have identical reference. numerals. for ease in comparing. the. disclosed. structures.

The speaker may be mounted in the circular apertured portion 125. of. the. wall. 12, asin Figure. l, and in such case, the baflle' members 18' and 20' are routed. out, as shown. in. Figure 3, to accommodate the inwardly protruding. portion. of the speaker. The speaker 34 which is conventional,.in such case is provided with amountnig flange 30A having apertured portions through whichsui'table. screws. or bolts pass to fasten such speaker. to the wall 12. Instead of mounting the speaker on the wall'12, the. speaker may be mounted within the centrally apertured'. portion. 14S- inthe wall 14 and in such case itis. not. necessary, ofcourse, that any one of the. bafiie members. be routed, since sufficient clearance. is available to accommodate the speaker when mounted on the wall. 14.

The baflde members may be secured to the walls of the enclosure by screws or nails, in the manner indicated in Figures 4 and and, if desired, suitable resilient material such as strips of hard sponge rubber 32 may be interposed between the baffie members and the Wall. or, if desired, between the baflle members themselves.

In the third modification illustrated in. Figures. 8 and9', thev enclosure or cabinet is adapted for placement in. the. corner of a room and for that reason is provided with a pairof'walls 4i} and 50'whichextend at right angles to.

each. other, suchwalls. 40 and 50 being attached. to the front Wall 52 and to the top andbottom walls. 5.3 and.5'4, respectively. In this case, only'one triangular bafilemember 60, similareither to bathe member 18 or. 20, is used. Bathe. member. 60 has its apex 60A disposed within the three-sided corner 50A of the enclosure 50 and its. base 60B abuttingthe inner. surface ofthefront wall 52 along a line Which extends parallel to the planes. oi the top. and bottom. walls.53 and 54 and midway between. the same.

The front wall 52 is. circularly apertured to. receive and.

to mount. a conventional speaker; and. to accommodate suchaspeaker, the triangular baflie. plate 60 is routed. out. at 60C to.- provide the. desired. clearance.

In. each of' the. modifications illustrated herein,. it is. observed that at. least one triangular shaped bathe. memher. is used to provide chambers in. an enclosure, such chambers. being defined by non-parallel walls so as. to obtain the above-indicated results.

While the particular embodiments of the presentinvention have been shown and. described, itwill be; obvious to those skilled in the art that changes. and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. A speaker enclosure comprising a rectangular box,.

apices disposed in difierent three-sided corners of said box, said difierent three-sided corners being defined by said first wall which is common to each of the three sided corners, the bases of said triangular bafiie members intersecting on a line corresponding to the diagonal of said second wall of said box, and said second wall being centrally apertured on said line to define a central apertured portion, and a speaker mounted in said apertured portion.

2. A speaker enclosure comprising a hollow body, said body having an internal: spacedefined byat least one three-sided. corner, a. triangularshaped. bafile. member disposed within said' box and having its apex disposed in said corner, and the'base-ofsaidatriangular-shaped bathe member intersecting a Wall of said box on a line to provide a plurality of compartments each defined by non-parallel walls, and said wall being centrally apertured on said line to define. a centralapertured portion, and. a speaker mounted'in said apertured'portion.

3. A speaker enclosure comprising three. walls defining a 'threewsided" corner, said enclosurehaving atfourth wall,

a triangularly-shaped b'afile member disposed. withinsaid.

box having its apex disposed in saidfthree-sided corner and'. having its. base contacting said fourth wall on astraight line to provide a. plurality of compartments. of non-parallel walls, and said fourth wall being. centrally apertured onsaid. lineto define a. central apertured. portion, and a speaker mounted insaid apertured portion.

4. A speaker enclosure comprising a box defined by at least four walls, three of said walls-defining a threesided' corner, a triangularly-shaped. bat-He. member having. its apex disposed in said corner and its base contacting.

the fourthwall' along a linewhich extends the full length of the fourth wall; and said fourth wall being. centrally apertured on saidline. to. define a. central apertured portion, and a speaker mounted. in said. apertured portion.

5. A speaker enclosure comprising a parallelepiped having six walls,. a first three-sided. corner defined, by a first, a second and a third. one of. said walls, a. second.

three-sided corner defined'bysaid' first, a. fourth and a.

fifth one of saidlwalls,a.pair oftriangularly-shaped bafide members, one of' said bafiie. membersv having. its. apex.

disposed in the. first-mentioned. corner. and the. apex of the other baffle member beingdisposed in. the other of said corners,.said bathe members both having. their bases.

intersecting ona line which corresponds to a diagonalof the sixth wall of saidparallelepiped, said sixth wall being centrally apertured on said line. tordefine a.central apertured. portion, and a speaker mounted in said apertured portion.

6. A speaker enclosure having. five walls, with the. planes of two of said walls intersecting at a. right. angle,v

said two walls and, a third wall defining a three-sided corner, a triangularly-shaped' bafiie. member having its. apex disposed in said' corner and having its. base contacting; a. fourth wall. of said enclosure along a line which extends substantially the fulllength of; said fourth. wall to. partition said enclosure into a. plurality of. compartments dc.- fined' by non-parallel'walls. said. fourthwall? being. centrally aperturedv on said line, to define a centralapertured portion, and a speaker mounted in said apertured portion.

References Cited in the file of this patent UNITED. STATES. PATENTS.

2,337,213" Topping Dec; 21, 1943 

